The reaction of 4,4′-dinitrostilbene-2,2′-disulfonic acid with potassium permanganate was studied in sodium bicarbonate medium, and optimum conditions for use of this reaction for direct volumetric determination of the studied substance with permanganate and with amperometric indication of the equivalence point were found. Electrometric indication using solid electrodes cannot be recommended because of the passivation of these electrodes, and indirect determination is not satisfactory because of the subsequent oxidation of the 1-sulfo-3-nitrobenzaldehyde produced. © 1979.
